Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

A control device for an electrically driven door is provided that can
enhance the sensitivity of detection of a door pinch state and that can
prevent a passenger from being pressed when the door pinch state occurs.
The control device includes a driving force instruction value producing
unit that outputs a driving force instruction value of the electrically
driven door, a state observing unit that estimates a mechanical resistant
force to a door driving system, a reference model that determines a
dynamic characteristic of the electrically driven door to the mechanical
resistant force estimated by the state observing unit, a gain compensator
that computes a control compensation value that makes an output of the
reference model coincide with an actual speed of the electrically driven
door; and an adder that adds the control compensation value computed by
the gain compensator to the driving force instruction value.

Claims:

1. A control device of an electrically driven door opened or closed by an
electric motor, the control device comprising: a driving force
instruction value producing unit that outputs a driving force instruction
value of the electrically driven door; a state observing unit that
estimates a mechanical resistant force to a door driving system of the
electrically driven door; a reference model that determines a dynamic
characteristic of the electrically driven door to the mechanical
resistant force estimated by the state observing unit; a gain compensator
that computes a thrust compensation value for making an output of the
reference model coincide with an actual speed of the electrically driven
door; and an adder that adds the thrust compensation value computed by
the gain compensator to the driving force instruction value outputted by
the driving force instruction value producing unit.

2. The control device of an electrically driven door as claimed in claim
1, further comprising an adder that adds the mechanical resistant force
of the door driving system as a compensation value of a door driving
force to the driving force instruction value, the mechanical resistant
force being estimated when the electrically driven door is normally
operated.

3. The control device of an electrically driven door as claimed in claim
2, wherein the mechanical resistant force of the door driving system
estimated for each position of the electrically driven door when the
electrically driven door is normally operated is used as the compensation
value of the door driving force.

4. The control device of an electrically driven door as claimed in claim
1, wherein the electrically driven door comprises a side sliding door of
a rail car.

5. A control device of an electrically driven door opened or closed by an
electric motor, the control device comprising: a driving force
instruction value producing unit that outputs a driving force instruction
value of the electrically driven door; a door driving mechanism that
drives the electrically driven door on a basis of the driving force
instruction value output from the driving force instruction value
producing unit; a state observing unit that estimates a mechanical
resistant force to the door driving mechanism; and a door pinch detecting
unit that detects a door pinch state when the mechanical resistant force
detected by the state observing unit exceeds a specified value.

6. The control device of an electrically driven door as claimed in claim
5, wherein the door pinch detecting unit detects the door pinch state
when a state where the mechanical resistant force of the door driving
mechanism estimated by the state observing unit continues for a specified
time.

7. The control device of an electrically driven door as claimed in claim
5, wherein the electrically driven door comprises a side sliding door of
a rail car.

8. A method of controlling an electrically driven door opened or closed
by an electric motor, the method comprising: generating a driving force
instruction value of the electrically driven door using a driving force
instruction value producing unit; estimating a mechanical resistant force
to a door driving system of the electrically driven door using a stage
observing unit; determining a dynamic characteristic of the electrically
driven door to the mechanical resistant force estimated by the state
observing unit using a reference model; computing a thrust compensation
value for making an output of the reference model coincide with an actual
speed of the electrically driven door using a gain compensator; and
adding the thrust compensation value computed by the gain compensator to
the driving force instruction value outputted by the driving force
instruction value producing unit using an adder.

9. The method of claim 8, further comprising adding the mechanical
resistant force of the door driving system as a compensation value of a
door driving force to the driving force instruction value using an adder,
the mechanical resistant force being estimated when the electrically
driven door is normally operated.

10. The method of claim 9, wherein the mechanical resistant force of the
door driving system estimated for each position of the electrically
driven door when the electrically driven door is normally operated is
used as the compensation value of the door driving force.

Description:

[0001] This application is a continuation of U.S. patent application Ser.
No. 12/547,829 filed Aug. 26, 2009; which claims the benefit of priority
to Japanese Patent Applications 2008-216775 & 2008-216776 both filed Aug.
26, 2008, the contents of each of which are incorporated herein by
reference in their entirety.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a control device for an
electrically driven door and, in particular, to a control device that
drives an electrically driven door safely when foreign matter is pinched
by the door.

[0003] In an electrically driven door driven by an electric motor, for
example, a side sliding door of a rail car, the detection that a
passenger or foreign matter, such as passenger's belonging, is pinched by
the door when the door is closed (a so-called "door pinch" state) is a
very important function in securing the safety of the passenger. For this
reason, a door pinch detecting device has been proposed to detect the
door pinch state.

[0004] JP-A 3-189265, for example, discloses a device that includes: a
speed detecting unit for detecting the opening/closing speed of a door; a
position detecting unit for detecting that the door is located at a
middle position in the opening/closing operation; a determination unit
that receives the detection results of the speed detecting unit and the
position detecting unit and that determines whether the opening/closing
speed of the door located at the middle position of the opening/closing
operation is zero, in a decreasing state, or in a minus state; and a
notification unit that outputs a signal for notifying that foreign matter
is pinched by the tip of the door when the determination unit determines
that the opening/closing speed of the door located at the middle position
of the opening/closing operation is zero, in the decreasing state, or in
the minus state ( ). Moreover, in the same patent document, a door pinch
detecting device is described that has a pressure sensing sensor disposed
in a rubber piece fitted to the tip of the rail car door, and which
detects foreign matter being pinched by the door by a change in pressure.

[0005] When the occurrence of door pinch is detected by the door pinch
detecting device of the type described above, either decreases the thrust
of the door, opens the door a specified distance in a direction to fully
open the door or the door is opened to a fully opened position. Using one
of these options, it is then possible to relieve a passenger pinched by
the door or to pull off the passenger's belongings being pinched by the
door.

[0006] However, in the above-described device, when it is determined that
the door is not brought to a totally closed position or that the
opening/closing speed of the door at a middle position in the
opening/closing operation is zero, in the decreasing state, or in the
minus state, a signal for notifying that foreign matter is pinched by the
tip of the door is output. Thus, as a result, the above-described device
is constructed so as to detect the door pinch state by detecting that the
door has been brought into the door pinch state, in other words, by
detecting that the door pinch state has already occurred. As a result,
the foreign matter pinched by the door continuously undergoes pressure
and, in particular, when a passenger getting on or off is pinched by the
door, the passenger continuously undergoes pressure until the door pinch
state is detected thereby causing the passenger to feel some pain due to
the applied pressure.

[0007] Moreover, to increase the sensitivity with which the door pinch
state is detected, the rigidity of the door, in particular, the rigidity
of rubber disposed at the tip of the door (hereinafter referred to as
"door tip rubber"), needs to be increased. Although the increase in the
rigidity of the rubber makes detection of the door pinch state easier, it
also results in increasing the pressing pain when the door pinch state
occurs, which presents a not-yet-solved problem that increasing the
pressing pain experienced by the passenger is not preferable from the
viewpoint of safety.

[0008] Thus, it would be desirable to provide a control device of an
electrically driven door that can increase the sensitivity with which the
door pinch state is detected, and which can prevent a passenger from
being pressed when the door pinch state occurs and the passenger is
pinched by the tip of the door.

[0009] Moreover, in an electrically driven door for a rail car, when a
phenomenon occurs that foreign matter is pulled into a gap between the
electrically driven door and a car body during a door opening/closing
operation (also referred to as "opening door pinch"), it is difficult to
determine whether or not the electrically driven door reaches a fully
open position, because a maximum opening size of the electrically driven
door cannot be accurately determined due to variations in the
manufacturing accuracy of the car body. Thus, there is presented a
not-yet-solved problem that the relate art cannot provide a more
effective determination means than one that uses a decrease in door speed
to determine the above-mentioned phenomenon.

[0010] Further, the door for a rail car is provided with a seal rubber for
preventing a draft entering from the gap of the door while the rail car
is running, and a damper for pressing the door in a direction vertical to
a direction in which the door is operated so as to prevent the door from
being rattled by the vibration caused when the rail car is running. Thus,
even when the door is normally operated, a mechanical resistant force to
an electric motor for driving the door varies from moment to moment
according to the position of the door in the operation of opening/closing
the door. Hence, when a door thrust is limited, it is difficult to manage
a final door thrust only by limiting the thrust or torque of the electric
motor, which is a not-yet-solved problem. In other words, there is
presented such a not-yet-solved problem that since an increase or
decrease in the mechanical resistant force varies a net door thrust, it
is likely that when the margin of the door thrust becomes insufficient,
normal operation will be prevented or that, when the door thrust becomes
excessive at the time of door pinch, safety will be compromised.

[0011] Accordingly, it would also be desirable to provide a control device
of an electrically driven door that can quickly detect the door pinch
state and that can manage the net thrust of the door also to a mechanical
resistant force when the door is operated.

SUMMARY OF THE INVENTION

[0012] The present invention provides a control device of an electrically
driven door that can enhance the sensitivity of detection of the door
pinch state and that can prevent a passenger from being pressed when the
door pinch state occurs and the passenger is pinched by the tip of the
door.

[0013] The invention further provides a control device of an electrically
driven door that can quickly detect the door pinch state and that can
manage the net thrust of the door also to a mechanical resistant force
when the door is operated.

[0014] Accordingly to a preferred embodiment of the invention, a control
device of an electrically driven door includes a driving force
instruction value producing unit that outputs a driving force instruction
value of the electrically driven door, a state observing unit that
estimates a mechanical resistant force to a door driving system of the
electrically driven door, a reference model that determines a dynamic
characteristic of the electrically driven door to the mechanical
resistant force estimated by the state observing unit, a gain compensator
that computes a thrust compensation value that makes an output of the
reference model coincide with an actual speed of the electrically driven
door; and an adder that adds the thrust compensation value computed by
the gain compensator to the driving force instruction value output by the
driving force instruction value producing unit.

[0015] According to a further preferred embodiment of the invention, a
control device of an electrically driven door further includes an adder
that adds the mechanical resistant force of the door driving system as a
compensation value of a door driving force to the driving force
instruction value, the mechanical resistant force being estimated when
the electrically driven door is normally operated.

[0016] According to a further embodiment of the invention, a control
device of an electrically driven door is provided, wherein the mechanical
resistant force of the door driving system estimated for each position of
the electrically driven door when the electrically driven door is
normally operated is used as the compensation value of the door driving
force.

[0017] Still further, a control device of an electrically driven door
opened or closed by an electric motor is preferably provided that
includes a driving force instruction value producing unit that outputs a
driving force instruction value of the electrically driven door, a door
driving mechanism that drives the electrically driven door on the basis
of the driving force instruction value output from the driving force
instruction value producing unit, a state observing unit that estimates a
mechanical resistant force to the door driving mechanism, and a door
pinch detecting unit that detects a door pinch state when the mechanical
resistant force detected by the state observing unit exceeds a specified
value.

[0018] Still further, a control device of an electrically driven door is
preferably provided, wherein the door pinch detecting unit detects the
state of door pinch when a state where the mechanical resistant force of
the door driving mechanism estimated by the state observing unit
continues for a specified time or more.

[0019] Still further, a control device of an electrically driven door is
preferably provided, wherein the door pinch detecting unit detects the
door pinch state when a value obtained by subtracting a previously set
offset value from the mechanical resistant force of the door driving
mechanism estimated by the state observing unit exceeds a specified value
or a state where the value exceeds the specified value continues for a
specified time or more.

[0020] Still further, a control device of an electrically driven door is
preferably provided, wherein an offset value for each position of the
electrically driven door is set as an offset value to be subtracted from
the mechanical resistant force of the door driving mechanism estimated by
the state observing unit.

[0021] Still further, a control device of an electrically driven door is
preferably provided, wherein an average value of the mechanical resistant
forces of the door driving mechanism that have been estimated by the
state observing unit when the electrically driven door has been opened or
closed until then is used as an offset value subtracted from the
mechanical resistant force of the door driving mechanism estimated by the
state observing unit.

[0022] Still further, a control device of an electrically driven door is
preferably provided, wherein the average value of the mechanical
resistant forces of the door driving mechanism that have been estimated
by the state observing unit is set for each position of the electrically
driven door.

[0023] Still further, the invention is preferably directed to a control
device of an electrically driven door, wherein the electrically driven
door has a construction of a side sliding door of a rail car.

[0024] According to the invention, the state observing unit estimates the
mechanical resistant force to the door driving system of the electrically
driven door, produces a reference model for determining the dynamic
characteristic of the electrically driven door to the estimated
mechanical resistant force, computes a thrust compensation value for
making the output of the reference model coincide with the actual speed
of the electrically driven door, and adds this thrust compensation value
to the driving force instruction value outputted by the driving force
instruction value producing unit. Thus, the net thrust of the
electrically driven door can be managed in such a way as to make the
behavior of the electrically driven door to the external force when the
state of door pinch occurs show a specified dynamic characteristic, which
can reduce an impact when the state of door pinch occurs. Hence, the
invention can produce the effect of providing the door that is preferably
safe in the operation of the door and that is friendly to passengers
getting on or off.

[0025] Moreover, according to the invention, the state observing unit
estimates a mechanical resistant force to the door driving mechanism for
driving the electrically driven door, and when the estimated mechanical
resistant force exceeds a specified value, the door pinch detecting unit
detects the state of door pinch. Hence, the invention can produce the
effect of quickly detecting the state of door pinch.

[0026] Further, such the mechanical resistant force of the door driving
system that is estimated when the electrically driven door is normally
operated is added as the compensation quantity of the door driving force
to the driving force instruction value, so that the net mechanical
resistant force that is applied to the electrically driven door and which
is caused by the external turbulence such as the occurrence of door pinch
can be estimated.

[0027] Other features, advantages, embodiments, etc. of the invention will
become apparent to those skilled in the art from the following detailed
description of the preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be described with reference to certain preferred
embodiments thereof and the accompanying drawings, wherein:

[0029] FIG. 1 is a general construction diagram in a case in which the
present invention is applied to an electrically driven door of a rail
car;

[0030]FIG. 2 is a block diagram to show the specific construction of a
control device in FIG. 1 in accordance with a first embodiment of the
invention;

[0031]FIG. 3 is a block diagram to show the specific construction of a
control device in accordance with a second embodiment of the invention;

[0032]FIG. 4 is a block diagram to show the specific construction of a
control device in accordance with a third embodiment of the invention;

[0033]FIG. 5 is a characteristic curve graph to show the door pinch
state;

[0034]FIG. 6 is a block diagram to show the specific construction of a
control device in accordance with a fourth embodiment of the invention;

[0035]FIG. 7 is a graph illustrating the relationship between thrust and
door velocity with respect to time;

[0036] FIG. 8 illustrates frictional forces as a door moves from a fully
open position to a fully closed position;

[0038] FIGS. 10 and 11 respectively illustrate examples of a lighter door
and a door with a padded edge, although illustrated separately, the two
models illustrated in FIGS. 10 and 11 can be combined in the reference
model; and

[0039] FIG. 12 illustrates an example of velocity control with
compensation for a lighter door.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] FIG. 1 is a block diagram to show the general construction of a
control device of an electrically driven door according to a first
embodiment of the invention, and FIG. 2 is a block diagram to show the
specific construction of the control device in FIG. 1. In FIG. 1, the car
body of a rail car is provided with an electrically driven door 1
including a door closing unit that passengers use at the time of getting
on or off the rail car and which is of a side sliding door type, and the
respective door units 1a and 1b of this electrically driven door 1 have a
door tip rubber 2 fixed to their tips on the sides to which the door
units are closed. Moreover, the rail car is provided with: a door
operator 3 including an electric motor for driving the electrically
driven door 1 and a door driving mechanism 13 for converting or
transmitting the driving force of the electric motor to the linear motion
of opening or closing the door; a coupling unit 4 for coupling the door
operator 3 to a door leaf; and a position/speed detector 14 that detects
the position and speed of the electrically driven door 1 and which
outputs position information p and door opening/closing speed information
v corresponding to the position and speed. The door driving mechanism 13
is driven by an electric driving system 12 including an electric power
converter such as an inverter built in a control unit 10 and of the
electric motor, thereby opening/closing or driving the electrically
driven door 1.

[0041] The control unit 10, as shown in FIG. 2, has a thrust instruction
producing unit 11 as a driving force instruction value producing unit
that has an opening/closing instruction c, the door position information
p, and the door opening/closing speed information v, inputted thereto,
the opening/closing instruction c being inputted from a door closing
control unit (not shown) and instructing the door to open or close, the
door position information p and the door opening/closing speed
information v being outputted from the position/speed detector 14. When
the opening/closing instruction c for opening or closing the door is
input to the thrust instruction producing unit 11, the thrust instruction
producing unit 11 performs a specified computation on the basis of the
door position information p and the door opening/closing speed
information v or refers to a control map to thereby compute a target
thrust instruction τ* and outputs the computed target thrust
instruction τ* to the electric driving system 12 constructed of the
inverter and the electric motor. The electric driving system 12 produces
a thrust f for opening or closing the door on the basis of the target
thrust instruction τ*, thereby driving the door operator 3 via the
door driving mechanism 13.

[0042] A thrust compensation value τM supplied from a gain compensator
18 to be described later is added to the target thrust instruction τ*
outputted from the thrust instruction producing unit 11 by an adder 19,
and the average value fem, which is supplied from a memory 16 to be
described later and which is an average value of external force
estimation values fe to estimate the sum of external forces applied to
the door driving mechanism 13, is added to the target thrust instruction
τ* by an adder 20, and the addition output of the adder 20 is
inputted to the electric driving system 12.

[0043] A compensated thrust instruction value τc obtained by adding
the thrust compensation value τm to the target thrust instruction
τ* outputted from the adder 19 is supplied to one input side of a
state observing unit 15, and the door opening/closing speed information v
detected by the position speed detector 14 is inputted to the other input
side of this state observing unit 15. The state observing unit 15
computes the external force estimation value fe on the basis of the
compensated target thrust instruction τc outputted from the adder 19
and the door opening/closing speed information v, the external force
estimation value fe being the sum of: a mechanical resistant force fm
caused by the friction or the like of the electrically driven door 1 to
the door driving mechanism 13; and an external force fd applied to the
electrically driven door 1 in a state where an obstacle is pinched by the
doors in the door pinch state. FIG. 7 is a graph illustrating the
relationship between thrust and door velocity with respect to time.

[0044] The external force estimation value fe computed by this state
observing unit 15 is supplied to the memory 16 and to a target value
response reference model unit 17. In the memory 16, the position
information p detected by the position/speed detector 14 is inputted to
the memory 16, and this position information p and history information
such as the number of recordings and the external force estimation values
fe are subjected in combination to a data processing by the use of
various mathematical techniques, such as an arithmetic averaging
technique, and then the average value fem of the external force
estimation values fe of the state observing unit 15 for the respective
positions of the electrically driven door 1 is stored. At this time, the
electrically driven door 1 is opened or closed in a state where the
electrically driven door 1 is normally lubricated and where an obstacle
is not pinched by the doors, that is, the external force fd is zero, and
the average value fe is stored in the memory 16. With this, the
mechanical resistant force fm caused by the friction or the like of a
sliding unit in the state where the electrically driven door 1 is
normally lubricated can be recognized. FIG. 8 illustrates the frictional
forces as the door moves from a fully open position to a fully closed
position. The memory 16 reads the average value fem at a position
corresponding to the position information p inputted from the
position/speed detector 14 and outputs the read average value fem to the
adder 20.

[0045] Moreover, the target value response reference model unit 17 to
which the external force estimation value fe outputted from the state
observing unit 15 is inputted expresses a mathematical reference model to
express the dynamic characteristic of a soft spring for absorbing an
impact when the door pinch state occurs and of the electrically driven
door 1 whose apparent inertia is reduced so as to reduce the impact when
the door pinch state occurs as the desirable dynamic characteristic of
the electrically driven door 1 to the external force.

[0046] The mathematical reference model is a motion equation that
expresses a desired door behavior. For example, if a door is particularly
light, the impact of being trapped by such a door is small and doesn't
caused much pain. Alternatively, if the edge of the door is padded with a
sponge like material, the pressure and pain of impact can be alleviated
to some degree. Such characteristics are expanded in the reference model
into a motion equation. By including an external force fe estimated by a
state observer into the model, a resulting vm simulated behavior when
someone has been trapped in the door can be generated. By controlling the
movement of the actual door so that is follows vm, it is possible for the
door to behave as if it were the specified door (i.e. lightweight,
padded, etc.) in the reference model. FIG. 9, for example, illustrates
normal door control, while FIGS. 10 and 11 respectively illustrate
examples of a lighter door and a door with a padded edge. Although
illustrated separately, the two models illustrated in FIGS. 10 and 11 can
be combined in the reference model.

[0047] A actual door opening/closing speed v is subtracted by a subtracter
21 from a speed vm acquired when the external force estimation value fe
estimated by the state observing unit 15 is inputted to this reference
model 17 to thereby compute a speed difference ΔV, and the computed
speed difference ΔV is supplied to the gain compensator 18.

[0048] The gain compensator 18 multiplies the inputted speed difference
ΔV by a specified compensation gain Kv to compute the thrust
compensation value rm and supplies the computed thrust compensation value
rm to the adder 19. At this time, when a proper characteristic is set as
the compensation gain Kv, the speed vm outputted from the target value
response reference model 17 can be made to coincide with the door
opening/closing speed v actually detected by the position/speed detector
14. Here, the compensation gain Kv is not limited to a proportional gain
of a sheer scalar quantity but may be a combination of proportional
compensation and integral compensation and further differential
compensation.

[0049] The operation of the above-mentioned first embodiment will now be
described. First, when a rail car is shipped from a factory or maintained
or checked, the electrically driven door 1 is repeatedly opened or closed
a specified number of times in a normal operating state where the
electrically driven door 1 is normally lubricated and where an obstacle
is not pinched by the door, and every time the position information p,
which is detected by the position/speed detector 14 when the electrically
driven door 1 is repeatedly opened or closed, is varied, the external
force estimation value fe of the state observing unit 15 is stored in
sequence in the memory 16 in combination with the number of histories and
the position information p, and a specified number of external force
estimation values fe for each piece of the stored position information p
are subjected to a mathematical averaging processing or a moving
averaging processing, whereby an average value fem for each piece of the
position information p is computed, and the computed average value fem is
stored in the memory 16 along with the position information p. When the
average value fem of the external force estimation value fe for each
piece of the position information p detected by the state observing unit
15 in this normal operating state is stored in the memory 16, the average
value fem of the external force estimation value fe in a state where the
external force fd is not applied to the door driving mechanism 13, that
is, the external force estimation value fe in a state where only the
mechanical resistant force fm caused by the friction and the like is
applied to the door driving mechanism 13 can be stored in the memory 16
for each piece of the position information p.

[0050] For this reason, when the rail car is actually stopped at a station
where passengers get on or off and the door opening/closing operation
instruction c is output to the thrust instruction producing unit 11 by
the door closing control unit, the thrust instruction producing unit 11
computes the target thrust instruction τ* for opening or closing the
electrically driven door 1 in a desired speed pattern on the basis of the
position information p detected by the position/speed detector 14 and the
door opening/closing speed information b and outputs the target thrust
instruction τ* to the adder 19.

[0051] The adder 19 has the thrust compensation value τm computed by
the gain compensator 18 inputted thereto, the thrust compensation value
τm being able to make the speed vm outputted from the target value
response reference model 17 coincide with the door opening/closing speed
v actually detected by the position/speed detector 14 as described above,
and this thrust compensation value τm is added to the target thrust
instruction τ*. Thus, it is possible to control the door in such a
way that the difference between the target value of the door speed and
the actual door opening/closing speed v becomes zero, in other words, the
electrically driven door 1 shows the dynamic characteristic specified by
the target value response reference model 17.

[0052] For this reason, when the external force fd increases, that is, the
door pinch state occurs, this external force fd can be correctly
estimated as the external force estimation value fe by the state
observing unit 15, and when the external force estimation value fe
responsive to this external force fd is estimated, the speed vm computed
by the use of the target value response reference model 17 can be made to
coincide with the actual door opening/closing speed v. For this reason,
when the dynamic characteristic of the electrically driven door 1 to the
external force applied to the electrically driven door 1, that is, to the
external force applied to the electrically driven door 1 when the door
pinch state occurs, is made, for example, a characteristic having
elasticity like a sponge, the actual door opening/closing speed v can be
controlled so as to become a speed responsive to the characteristic and
hence an impact caused when the state of door pinch occurs can be
reduced. FIG. 12 illustrates an example of velocity control with
compensation for a lighter door.

[0053] Thus, when the above-mentioned characteristic of the electrically
driven door 1 is combined with the increasing of the elasticity of the
door tip rubber 2, it is possible to improve a detection sensitivity with
which the door pinch state is detected and to prevent an increase in the
impact caused when the door pinch state occurs. For this reason, this is
desirable for the safe operation of the door and there is provided a door
friendly to the passenger.

[0054] In addition, the average value fem of the external force estimation
value fe responsive to the mechanical resistant force fm applied to the
door driving mechanism 13 for each piece of position information p at the
time of normal operation is outputted from the memory 16. Then, the
average value fem is added to the compensated target thrust instruction
τc by the adder 20 and the added value is supplied to the electric
driving system 12, so that the thrust f into which the mechanical
resistant force fm caused by the friction and the like is incorporated
can be produced by the electric driving system 12, and the thrust f is
supplied to the electric motor constructing the electric driving system
12. With this, the mechanical resistant force fm applied to the door
driving mechanism 13 can be canceled, which makes it possible to manage a
net thrust that the electrically driven door 1 produces to the outside.

[0055] A second embodiment of the invention will be described with
reference to FIG. 3. The second embodiment has the same construction as
the first embodiment except that the state quantity E of the electric
driving system 12 such as voltage or current is used in place of the
thrust instruction τc inputted to the electric driving system 12 as
the input of the state observing unit 15. The units corresponding to the
units in FIG. 2 are denoted by the same reference symbols and the
detailed description of the units will be omitted.

[0056] In the second embodiment, the external force estimation value fe
computed by the state observing unit 15 by the use of the state quantity
E such as voltage or current to be supplied to the electric motor of the
electric driving system 12 becomes the same value as in the first
embodiment described above, and the same operation and effect as in the
first embodiment can be produced. In this regard, the construction of the
state observing unit 15 is not limited to the constructions of the first
and second embodiments described above, but if an arbitrary state
observing unit has a construction capable of estimating the external
force (fm+fd) applied to the door driving mechanism 13, the state
observing unit can be employed.

[0057] A third embodiment of the invention will be described with
reference to FIG. 4. Here, the units having the same constructions as the
units in the first embodiment described above are denoted by the same
reference symbols and the detailed description of the units will be
omitted.

[0058] The control unit 10, as shown in FIG. 4, has a thrust instruction
producing unit 11 as a driving force instruction value producing unit
that has the opening/closing operation instruction c and the door
position information p and the door opening/closing speed information v
inputted thereto, the opening/closing operation instruction c being
inputted from a door closing control unit (not shown) and instructing the
door to open or close, the door position information p and the door
opening/closing speed information v being outputted from the
position/speed detector 14. When the opening/closing operation
instruction c for opening the door or closing the door is inputted to
this thrust instruction producing unit 11, the thrust instruction
producing unit 11 performs a specified computation on the basis of the
door position information p and the door opening/closing speed
information v or refers to a control map to thereby compute the target
thrust instruction τ* and outputs the computed target thrust
instruction τ*. Moreover, when the thrust instruction producing unit
11 has a door pinch detection signal Obst of a logic value "1" inputted
thereto from a door pinch detecting unit 27 to be described later, the
thrust instruction producing unit 11 sets the target thrust instruction
τ* at a comparatively small specified value.

[0059] The target thrust instruction τ* outputted from the thrust
instruction producing unit 11 is supplied to the adder 20, and the
mechanical resistant force estimation value fem as a compensation
quantity supplied from the memory 16, which will be described later, is
added to the target thrust instruction τ* by the adder 20, and the
compensated target thrust instruction value τc of the added output is
outputted to the electric driving system 12 constructed of the inverter
and the electric motor, and the thrust f for opening/closing the door is
produced by the electric driving system 12 on the basis of the target
thrust instruction τ* to drive the door operator 3 via the door
driving mechanism 13.

[0060] Moreover, the compensated target thrust instruction value τc
outputted from the adder 20 is supplied to one input side of the state
observing unit 15. The door opening/closing speed information v detected
by the position/speed detector 14 is supplied to the other input side of
this state observing unit 15. The state observing unit 15 computes the
mechanical resistant force estimation value fe on the basis of the
compensated target thrust instruction value τc outputted from the
adder 20 and the door opening/closing speed information v, the mechanical
resistant force estimation value fe being the total sum of the mechanical
resistant force fm such as the friction of the electrically driven door 1
to the door driving mechanism 13 and the mechanical resistant force fd
caused by external turbulence applied to the electrically driven door 1
when the door pinch state occurs.

[0061] The mechanical resistant force estimation value fe computed by this
state observing unit 15 is supplied to the memory 16 and to the door
pinch detecting unit 27. In the memory 16, the position information p
detected by the position/speed detector 14 is input, and this position
information p and the history information such as the number of
recordings and the mechanical resistant force estimation value fe are
subjected to a data processing in combination by the use of various
mathematical techniques such as an arithmetic averaging technique, and
then the average value fem of the mechanical resistant force estimation
values fe of the state observing unit 15 for the respective positions of
the electrically driven door 1 is stored. At this time, when the door is
opened or closed in a state where the electrically driven door 1 is
normally lubricated and where an obstacle is not pinched by the door,
that is, the mechanical resistant force fd caused by the external
turbulence is zero and the average value fem is stored in the memory 16,
only the mechanical resistant force fm from which the mechanical
resistant force fd caused by the external turbulence such as the door
pinch state is removed, that is, which is caused by the friction of the
sliding unit in the normal state of the electrically driven door 1 can be
recognized. Then, the memory 16 reads the mechanical resistant force
average value fem at a position corresponding to the position information
p inputted from the position/speed detector 14 and outputs the read
mechanical resistant force average value fem to the adder 20.

[0062] Moreover, the mechanical resistant force estimation value fe
outputted from the state observing unit 15 and the mechanical resistant
force average value fem outputted from the memory 16 are inputted to the
door pinch detecting unit 27. The door pinch detecting 27 determines
whether or not a value obtained by subtracting the mechanical resistant
force average value fem as an offset value inputted from the memory 16
from the mechanical resistant estimation value fe inputted from the state
observing unit 15 exceeds a previously set threshold value fth. When
fe-fem≦fth, the door pinch detecting unit 27 determines that the
door pinch state does not occur and outputs a door pinch detection signal
Obst of a logic value "0" to the thrust instruction producing unit 11,
whereas when fe-fem>fth, the door pinch detecting unit 27 determines
that the door pinch state occurs and outputs a door pinch detection
signal Obst of a logic value "1" to the thrust instruction producing unit
11.

[0063] Next, the operation of the above-mentioned third embodiment will be
described. First, when a rail car is shipped from a factory or maintained
or checked, the electrically driven door 1 is repeatedly opened or closed
a specified number of times in a normal operating state where the
electrically driven door 1 is normally lubricated and where an obstacle
is not pinched by the door, and every time the position information p,
which is detected by the position/speed detector 14 when the electrically
driven door 1 is repeatedly opened or closed, is varied, the external
force estimation value fe of the state observing unit 15 is stored in
sequence in the memory 16 in combination with the number of histories and
the position information p. A specified number of external force
estimation values fe for each piece of the stored position information p
are subjected to a mathematical averaging processing or a moving
averaging processing, whereby an average value fem for each piece of the
position information p is computed, and the computed average value fem is
stored in the memory 16 along with the position information p.

[0064] When the average value fem of the external force estimation values
fe for each piece of the position information p detected by the state
observing unit 15 in the normal operating state is stored in the memory
16 in this manner, the average value fem of the mechanical thrust
estimation value fe in a state where the mechanical resistant force fd
caused by the external turbulence developed when the door pinch state
occurs is not applied to the door driving mechanism 13, that is, the
mechanical thrust estimation value fe in a state where only the
mechanical resistant force fm caused by the friction and the like is
applied to the door driving mechanism 13 can be stored in the memory 16
for each piece of the position information p.

[0065] For this reason, when the rail car is actually stopped at a station
where passengers get on or off and the door opening/closing operation
instruction c is outputted to the thrust instruction producing unit 11 by
the door closing control unit, this thrust instruction producing unit 11
computes the target thrust instruction τ* for opening or closing the
electrically driven door 1 in a desired speed pattern on the basis of the
position information p detected by the position/speed detector 14 and the
door opening/closing speed information b and outputs the computed target
thrust instruction τ* to the adder 20.

[0066] The mechanical thrust average value fem for each piece of the
position information p of the electrically driven door 1, which is
previously stored in the memory 16 as described above, is inputted to the
adder 20, so that the compensated target thrust instruction τc
obtained by adding the mechanical thrust average value fem to the target
thrust instruction τ* is supplied to the electric driving system 12.
Hence, the thrust f into which the mechanical resistant force fm such as
friction and the like is incorporated can be produced by the electric
driving system 12, and the thrust f is supplied to the electric motor
constructing the electric driving system 12. With this, the mechanical
resistant force fm applied to the door driving mechanism 13 can be
canceled, which makes it possible to manage a net thrust that the
electrically driven door 1 produces to the outside.

[0067] At this time, in a state where the door pinch state does not occur,
the mechanical resistant force fd caused by the external turbulence
applied to the door driving mechanism 13 is nearly equal to zero, and
only the mechanical resistant force fm caused by the friction and the
like is applied to the door driving mechanism 13. For this reason, the
state observing unit 15 has the door opening/closing speed information v
of the door driving mechanism 13 and the compensated target thrust
instruction τc inputted thereto, the door opening/closing speed
information v not undergoing the effect of the mechanical resistant force
fd produced by the external turbulence, the compensated target thrust
instruction τc being obtained by adding the mechanical resistant
force average value fem corresponding to the mechanical resistant force
fm to the thrust instruction τ*, so that the mechanical resistant
force estimation value fe computed by the state observing unit 15 is
nearly equal to zero and is inputted to the door pinch detecting unit 27.
For this reason, because the inputted mechanical resistant force
estimation value fe is nearly equal to zero, fe-fem≦fth. Thus, the
door pinch detecting unit 27 determines that the door pinch state does
not occur and hence outputs the door pinch detection signal Obst of a
logic value "0" to the thrust instruction producing unit 11.

[0068] For this reason, the thrust instruction producing unit 11 computes
the target thrust instruction τ* of the speed pattern based on the
position information p and the door opening/closing speed information v,
which are detected by the position/speed detector 14, and outputs the
computed target thrust instruction τ* to the adder 20. Thus, the
electric driving system 12 produces the door thrust f to open or close
the electrically driven door 1 via the door driving mechanism 13.

[0069] In a state where the electrically driven door 1 is driven to, for
example, to the closed state in this normal state, as shown by timing t1
in FIG. 5, the door thrust f outputted from the electric driving system
12 shows a low value and the mechanical resistant force (fm+fd) to the
door driving mechanism 13 also becomes a small value of only the
mechanical resistant force fm caused by the friction and the like. Thus,
the door opening/closing speed v becomes a usual comparatively high
speed.

[0070] From this normal state, when the door pinch state of door pinch in
which a passenger or a passenger's belonging is pinched by the
electrically driven door 1 occurs at timing t2, the mechanical resistant
force fd caused by the occurrence of the door pinch state increases
rapidly and hence the mechanical resistant force (fm+fd) to the door
driving mechanism 13 increases sharply as shown in FIG. 5.

[0071] At this time, in the case of a construction in the related art that
does not employ the door pinch detecting unit 27, the door driving
mechanism 13 itself has a specified quantity of momentum and hence the
door opening/closing speed v does not decrease immediately but gradually
decreases. Moreover, as the door opening/closing speed v decreases, the
electric driving system 12 of the electrically driven door 1 compensates
the thrust, so that the door opening/closing speed v decreases further
slowly. That is, in a mode in the related art in which the door pinch
state is detected on the basis of a decrease in the door opening/closing
speed or an increase in the driving current of a linear motor 3, the
state of door pinch is detected, for example, after timing t3 shown in
FIG. 3 and hence the detection of the door pinch state is delayed. Thus,
when a unit of the body of a passenger getting on or off is pinched by
the electrically driven door 1, the part of the body is continuously
pressed and raises a high possibility that a pain as a result of the
pressing will develop.

[0072] In contrast to this, in this embodiment, the door pinch detecting
unit 27 has the mechanical resistant force estimation value fe and the
mechanical resistant force average value fem as an offset value inputted
thereto, the mechanical resistant force estimation value fe being
estimated by the state observing unit 15, the mechanical resistant force
average value fem being stored in the memory 16 and corresponding to only
the mechanical resistant force fm that is caused by the friction and the
like in the normal state and that does not include the mechanical
resistant force fd caused by the external turbulence of the state of door
pinch. Thus, when the door pinch state occurs at the timing t2 to rapidly
increase the mechanical resistant force (fm+fd), as shown in FIG. 3, the
mechanical resistant force estimation value fe output from the state
observing unit 15 also rapidly increases. For this reason, in the door
pinch detecting unit 27, at timing t2' when the value (fe-fem) obtained
by subtracting the mechanical resistant force average value fem from the
mechanical resistant force estimation value fe becomes a state that
exceeds the threshold value fth, the door pinch detection signal Obst is
turned to a logic value "1" from a logic value "0". Since this door pinch
detection signal Obst is supplied to the thrust instruction production
unit 11, the thrust instruction τ* having been computed until then by
the thrust instruction production unit 11 is changed to a low thrust set
value previously set to thereby prevent the door thrust f from
increasing. With this, even when a part of the body of the passenger
getting on or off is pinched by the electrically driven door 1, it is
possible to make sure that pressure is not applied to the the part of the
body being pinched.

[0073] In this manner, in the detection of the door pinch state in the
related art, the occurrence of the door pinch state is detected by a
decrease to a certain level of the door speed, for example, the stoppage
of the electrically driven door 1, which is caused as a result of the
occurrence of the door pinch, or by the fact that the electrically driven
door 1 is not brought to a totally closed position 1 by an obstacle. In
contrast to this, in this embodiment, the occurrence of the door pinch
state can be detected on the basis of an increase in the mechanical
resistant force caused by the occurrence of the door pinch state and
hence the door pinch state can be detected more quickly than in the
related art. As a result, even when the part of the body of the passenger
getting on or off is pinched by the door, the safe operation of relieving
door pinch, such as decreasing the door thrust, can be performed more
quickly and hence the safety of the door can be further enhanced.

[0074] Further, the previously set mechanical resistant force or the
mechanical resistant force previously estimated by the state observing
unit 15 is added to the thrust instruction τ* and the added thrust
instruction is inputted to the state observing unit 15, so that the net
mechanical resistant force applied to the electrically driven door 1 by
the external turbulence such as the occurrence of the state of door pinch
can be estimated and hence the sensitivity and the detection accuracy
with which the state of door pinch can be detected can be enhanced.

[0075] Moreover, the door pinch detecting unit 27 detects not only the
door pinch state but also a state where a part of the body of the
passenger or a passenger's belonging is pulled into a door guard when the
electrically driven door 1 is opened, the so-called opening door pinch
phenomenon because the mechanical resistant force estimation value fe
estimated by the state observing unit 15 increases also in the opening
door pinch phenomenon.

[0076] Still further, the thrust of the electrically driven door 1 is
managed by previously canceling the mechanical resistant force fm of the
electrically driven door 1 that is varied according to the door position
p when the electrically driven door 1 is opened or closed. Thus, the
safety of the electrically driven door 1 and the certainty of the door
operation can be achieved at the same time. Thus, it is possible to
detect the door pinch state with high sensitivity and quickly, and it is
possible to provide an electrically driven door friendly to the
passengers getting on and off.

[0077] A fourth embodiment of the invention will be described with
reference to FIG. 6. The fourth embodiment has the same construction as
the above-mentioned third embodiment except that in place of the thrust
instruction τc given to the electric driving system 12, the state
quantity E of the electric driving system 12 such as voltage or current
is used as an input to the state observing unit 15. The units
corresponding to the units in FIG. 4 are denoted by the same reference
symbols, and the detailed description of the units will be omitted.

[0078] In the fourth embodiment, the external force estimation value fe
computed by the state observing unit 15 by the use of the state quantity
E such as voltage or current to be supplied to the linear motor of the
electric driving system 12 becomes a value nearly equal to that in the
first embodiment, and hence the same operation and effect as in the first
embodiment can be produced. In this regard, the above-mentioned first and
second embodiments have been described with respect to a case in which
when the value obtained by subtracting the mechanical resistant force
average value fem as the offset value stored in the memory 16 from the
mechanical resistant force estimation value fe estimated by the state
observing unit 15 exceeds the threshold value fth, the door pinch
detecting unit 27 determines that the door pinch state occurs, but the
invention is not limited to this. The door pinch detecting unit 27 may
determine that when a state in which the value obtained by subtracting
the mechanical resistant force average value fem from the mechanical
resistant force estimation value fe exceeds the threshold value fth
continues for a specified time, the state of door pinch occurs. In this
case, even when the threshold value fth is set at a value smaller than
the values in the third and fourth embodiments, it is possible to prevent
a false determination of the door pinch state. Here, the specified time
is set shorter than a detection time in the relate art.

[0079] Moreover, the third and fourth embodiments have been described with
respect to a case in which the door pinch detecting unit 27 subtracts the
mechanical resistant force average value fem stored in the memory 16 as
the offset value from the mechanical resistant force estimation value fe
outputted from the state observing unit 15, but the invention is not
limited to this. An offset value previously set for each position of the
electrically driven door 1 can be also used as the offset value.

[0080] Further, the construction of the state observing unit 15 is not
limited to the construction of the third and fourth embodiments, but an
arbitrary state observing unit can be employed, if the state observing
unit has a construction capable of correctly estimating the external
force (fm+fd) applied to the door driving mechanism 13.

[0081] Still further, the first to fourth embodiments have been described
with respect to a case in which the invention is applied to the
electrically driven door 1 of the rail car, but the invention is not
limited to this. The invention can be applied also to an electrically
driven door mounted in a vehicle such as an automobile. Further, the
invention can be applied not only to a door of a construction of a side
sliding door but also to a door of the other construction.

[0082] Still further, the first to fourth embodiments have been described
with respect to a case in which the invention is applied to the
electrically driven door 1 constructed of the rotary electric motor and
the door driving mechanism 13 for converting the rotational force of the
rotary electric motor to the linear motion of the door, but the invention
is not limited to this. The invention can be applied also to a case in
which the door is directly driven by a leaner motor moving linearly.

[0083] The invention has been described with reference to certain
preferred embodiments thereof. It will be understood, however, that
further modifications and variations are possible within the scope of the
appended claims. For example, it will be understood that the various
components and units of the described embodiments may be implemented
using discrete hardware components, firmware or programmable devices
employing software modules to perform the various illustrated functions.
In other words, the invention is not limited to specific structural
components utilized to implement the functions performed by the
illustrated embodiments, but instead, can be implemented utilizing any
combination of physical devices and components.

[0084] This application is based on and claims priority to Japanese Patent
Applications JP 2008-216775, filed on Aug. 26, 2008 and JP 2008-216776,
filed on Aug. 26, 2008. The disclosure of the priority applications in
their entirety, including the drawings, claims, and the specification
thereof, is incorporated herein by reference